About as many philosophies about micronutrient management in crop production exist as there are micronutrients. Clear insight into key micronutrients, their plant functions and soil interactions, and product use to balance plant nutrition, can help you address customer questions.

“It is extremely important to be able to recognize and correct micronutrient deficiencies. When micronutrients become a limiting factor, water, fertilizer and other high-energy production inputs may be wasted. A plant will only grow and develop to the extent that its most limiting growth factor will allow,” said David Mengel, Kansas State University soil fertility and nutrient management specialist. “For example, a corn crop might be unable to utilize the last 20 pounds of nitrogen applied if it does not have adequate supplies of micronutrients.”

Seven micronutrients are required by plants, according to Mengel; zinc (Zn), manganese (Mn), copper (Cu), iron (Fe), boron (B), molybdenum (Mo) and chlorine (Cl). 

Bob Yanda, Midwestern BioAg vice president of growth and development, labels zinc, copper, manganese, iron and boron as the base micronutrients. Midwestern BioAg works with farmers to improve soils through balanced nutrition by adding the right nutrients for the crop and situation.

“All of these micronutrients have specific functions in plants, and play important roles. ‘Yield chasers’ know that all are essential if you want to take yields to the next level,” he said.  “Micronutrients control enzymes and everything that moves in the plant. The plant is the factory producing the grain while enzymes control the rate and speed of movement of nutrients in the plant. Micronutrients control the functions of the enzymes.”

Know Your Micronutrients

Yanda outlines critical functions of the primary micronutrients:

• Zinc helps with phosphorus uptake and use and helps determine leaf size, which assists the plant with reaching genetic potential and maximizing yield and photosynthesis.  Plants deficient in zinc can suffer from shortened internodes and stunted leaf growth.

• Manganese is important to flowering and pollination and nitrogen translocation. It aids in chlorophyll development. Soybeans require more manganese because their nodules produce nitrogen, and manganese helps nitrogen move from nodule to bean in the pod.   

• Iron aids chlorophyll and nodule formation. Many soils are high in iron because it is bound tightly in the soil and is hard to exchange. Iron chlorosis occurs in high pH soils. 

• Copper is the immune system of the plant, and builds immunity from the inside out. 

• Boron assists with calcium mobility for nutrients to move through roots into the plant.  Boron is involved in sugar translocation, root growth and extended pollen production.